How to Fix BOOTMGR is missing (Windows Boot Manager)
Quick Answer
The 'BOOTMGR is missing' error indicates that the Windows Boot Manager cannot be found or loaded, preventing the operating system from starting. This often occurs due to incorrect boot order, corrupted boot files, or a failing hard drive. The fastest fix often involves checking the boot order in the BIOS/UEFI settings or performing a Startup Repair using Windows installation media.
What Causes This Error
- Incorrect boot order in BIOS/UEFI settings, causing the system to attempt booting from a non-bootable device.
- Corrupted or missing BOOTMGR files on the primary boot partition.
- Damaged or loose hard drive data cables, preventing proper detection of the boot drive.
- A failing or damaged hard disk drive where the operating system is installed.
- Corrupted Master Boot Record (MBR) or Boot Configuration Data (BCD).
- Installation of a new operating system or partition changes that interfere with the existing boot configuration.
Step-by-Step Fixes
1Verify Boot Order in BIOS/UEFI Settings
- Restart the computer.
- Immediately press the designated key to enter BIOS/UEFI Setup (commonly F2, F10, F12, DEL, or ESC). The specific key is often displayed on the screen during startup.
- Navigate to the 'Boot', 'Boot Order', or 'Startup' tab/section.
- Ensure that the hard drive containing the Windows installation is listed as the primary boot device. If using a USB drive for repair, ensure it is prioritized.
- Save changes and exit BIOS/UEFI, then allow the computer to restart.
2Perform Windows Startup Repair to Fix BOOTMGR is missing
- Insert your Windows installation media (USB drive or DVD) into the computer.
- Restart the computer and boot from the installation media. You may need to adjust the boot order in BIOS/UEFI.
- Select your language, time, and keyboard input, then click 'Next'.
- Click 'Repair your computer' in the bottom-left corner.
- Select 'Troubleshoot' > 'Advanced options' > 'Startup Repair' (or 'Automatic Repair'). Allow the process to complete, which may take some time.
3Rebuild the Boot Configuration Data (BCD) Manually
- Boot from your Windows installation media and navigate to the 'Repair your computer' option as described in the Startup Repair fix.
- Select 'Troubleshoot' > 'Advanced options' > 'Command Prompt'.
- At the command prompt, type 'bootrec /rebuildbcd' and press Enter.
- If prompted to add an installation to the boot list, type 'Y' and press Enter.
- Type 'exit' and press Enter, then restart your computer.
4Write a New Master Boot Record (MBR)
- Boot from your Windows installation media and access the 'Command Prompt' as outlined in the previous fixes.
- In the command prompt, type 'bootrec /fixmbr' and press Enter.
- Next, type 'bootrec /fixboot' and press Enter.
- Type 'exit' and press Enter, then restart your computer to check if the issue is resolved.
Frequently Asked Questions
What does 'BOOTMGR is missing' mean?
This error message indicates that the Windows Boot Manager (BOOTMGR) file, which is essential for starting the operating system, cannot be located or loaded by the computer's BIOS/UEFI. This prevents Windows from booting up successfully.
Can a loose cable cause the 'BOOTMGR is missing' error?
Yes, a loose or faulty data cable connecting your hard drive to the motherboard can prevent the system from detecting the boot drive, leading to the 'BOOTMGR is missing' error. Checking and reseating these cables is a valid troubleshooting step.
Do I need a Windows installation disc to fix this error?
In most cases, yes. Many of the common fixes for 'BOOTMGR is missing', such as Startup Repair, rebuilding the BCD, or fixing the MBR, require booting from a Windows installation DVD or USB drive to access the recovery environment and command prompt.
Is 'BOOTMGR is missing' a sign of a failing hard drive?
It can be. While often caused by software issues or incorrect boot settings, a failing hard drive can also lead to corrupted boot sectors or inaccessible BOOTMGR files. If other fixes do not work, testing the hard drive's health is recommended.